I have read the UKvisas guidelines and Liam Byrne's letter to ILPA and these seem to confirm that getting served and IS151A or B does not mean the person was removed and that it is perfectly possible for such people to leave voluntarily?
However, i've read two of Transpondia's posts which suggested that getting served with an IS151b means a 10 years ban even if you leave voluntarily.
Is this truly the case?
Here is what the entry clearance guidelines say - and I quote:
http://www.ukvisas.gov.uk/en/ecg/chapte ... 0seventeenRemember that making a decision to remove a person (Form IS 151B), or issuing a notice identifying him as an immigration offender (IS 151A) does not in itself mean that the applicant has been removed from the country. It is perfectly possible for someone to leave the country voluntarily after a decision has been taken to remove him. You therefore need to be satisfied that the applicant was actually removed before
deciding that the concession does not apply to him